جستجوی مقالات مرتبط با کلیدواژه « amino acid » در نشریات گروه « پزشکی »

Altered concentrations of cerebrospinal fluid (CSF) and blood amino acids may be related to epilepsy or the severity of the seizure. In the present study, we assessed the concentrations of amino acids in CSF and plasma in neonates with refractory seizures.

In this prospective cohort study, 27 neonates aged 1 to 56 days with refractory seizures were included. Blood and CSF samples were collected from each neonate within 24 hours after receiving 2nd antiseizure medications. All plasma and CSF samples were sent to the laboratory to measure amino acid concentrations. The associations between CSF and plasma amino acid levels with different variables were evaluated.

Except for leucine (P=0.15) and isoleucine (P=0.07), the levels of all amino acids were significantly higher in plasma than CSF. Significant associations were observed between types of seizure and plasma citrulline (P=0.008) and leucine concentrations (P=0.04). The mean of CSF glutamic acid was also statistically different among neonates with different EEG results (P=0.02).

Our findings indicate that several plasma and CSF amino acids could be candidate biomarkers for neonatal refractory seizures. Further studies with larger sample size are to confirm our findings.

 The biggest problem in the management of patients with Helicobacter pylori infections is resistance to the first-line antibiotic drug metronidazole. Several mechanisms underlie the resistance of H. pylori to metronidazole, and one of them is mutations in the rdxA gene encoding the nicotinamide adenine dinucleotide phosphate (NADPH) protein. Therefore, we characterized the rdxA gene amplified by PCR from gastric paraffin biopsies.

 This is an explorative study using 34 gastric paraffin biopsies that were H. pylori positive in a real-time PCR assay. To analyze the rdxA gene, we conducted nested PCR of a gene fragment, followed by DNA sequencing to analyze amino acid changes and protein structure analysis.

 Of the 34 H. pylori-positive paraffin biopsies, 5 were positive for the rdxA gene fragment. The amino acid change analysis showed that the NADPH protein had substitutions, insertions, frameshifts, and premature stop codons. Two novel amino acid insertions were found. The protein structure analysis showed that the NADPH protein with substitutions had amino acid changes forming 2 pockets for active sites. The NAPDH protein with substitutions and the 2 novel insertions showed the loss of one pocket.

 The present study reports on the genetic analysis of the rdxA gene showing DNA sequence diversity. Two amino acid insertions in the NADPH gene are a unique finding, and their effect on antibacterial-resistant phenotype needs to be investigated in future studies.

 Nearly all cases admitted to intensive care units (ICUs) suffer from poor nutritional status. Accordingly, the type of parenteral nutrition administered can influence these patients’ health conditions.

 This study aimed to compare the effects of parenteral nutrition with the amino acid alone and amino acid-intralipid combination on vital signs and rate of diuresis in ICU patients.

 This prospective cohort study was conducted over two years, from March 2021 to March 2023. Patients under intravenous nutrition with amino acid (Group A) and amino acid-intralipid (Group B) for three days (as ordered by the ICU specialist) were examined. The patients' vital signs and laboratory findings were recorded before and after the nutrition. The data were analyzed using SPSS v. 26.

 The patients were homogeneous regarding age, sex, disease history, and diagnosis (P < 0.05). After parenteral feeding, urine and blood urea nitrogen/creatinine ratio respectively increased and decreased in Group B. Moreover, the serum bilirubin level significantly decreased in Group B, and SGOT and SGPT increased in Group A. In addition, the breathing rate significantly increased in Group A after intravenous feeding (P < 0.001).

 Although intravenous amino acid-intralipid nutrition increased and decreased urine and blood urea nitrogen/creatinine, respectively, the patients who received amino acid alone also experienced an increase in urine volume and respiratory rate. Therefore, intravenous amino acid nutrition alone can be cost-effective.

Stress may have an important role in the origin and progress of depression and can impair metabolichomeostasis. The one-carbon cycle (1-CC) metabolism and amino acid (AA) profile are some of the consequencesrelated to stress. In this study, we investigated the Paroxetine treatment effect on the plasma metabolite alterationsinduced by forced swim stress-induced depression in mice.

In this experimental study that was carried out in 2021, thirty male NMRI mice (6-8 weeksage, 30 ± 5 g) were divided into five groups: control, sham, paroxetine treatment only (7 mg/kg BW/day), depressioninduction, and Paroxetine+depression. Mice were subjected to a forced swim test (FST) to induce depression and thenwere treated with Paroxetine, for 35 consecutive days. The swimming and immobility times were recorded during theinterventions. Then, animals were sacrificed, plasma was prepared and the concentration of 1-CC factors and twentyAAs was measured by spectrophotometry and high-performance liquid chromatography system (HPLC) techniques.Data were analyzed by SPSS, using One-Way ANOVA and Pearson Correlation, and P<0.05 was considered significant.

Plasma concentrations of phenylalanine, glutamate, aspartate, arginine, ornithine, citrulline, threonine,histidine, and alanine were significantly reduced in the depression group in comparison with the control group.The Homocysteine (Hcy) plasma level was increased in the Paroxetine group which can be associated withhyperhomocysteinemia. Moreover, vitamin B12, phenylalanine, glutamate, ornithine, citrulline, and glycine plasmalevels were significantly reduced in the depression group after Paroxetine treatment.

This study has demonstrated an impairment in the plasma metabolites’ homeostasis in depression andnormal conditions after Paroxetine treatment, although, further studies are required.

The need for amino acids increases significantly during pregnancy, and receiving sufficient amounts of different amino acids can prevent the pregnancy outcomes in the women fertilized by IVF. The present study investigated the effect of nutrition education on amino acid intake in women fertilized by IVF.

The present study is a quasi-experimental study with participation of 170 women fertilized by IVF, referred to the selected infertility clinic in Tehran in 2018. Sampling was performed using convenience method, and allocation of intervention and control groups was done by simple random method. Two questionnaires including lifestyle questionnaire in terms of nutrition and eating habits and questionnaire of 24-hour food recalls before and after the educational intervention in 6 sessions were used to collect information. Data were analyzed using descriptive statistics and T test by SPSS 20 and Nutritionist 4 (N4).

Based on the findings of this study, women aged 19 to 45 years in the two investigated groups showed significant changes in the intake of two amino acids, tyrosine, and valine, as in the intervention group, the amino acid tyrosine increased by 173 units (P=0.004), and in the control group, the amino acid valine had a decrease of 529 units (P=0.005)..

It seems that educational interventions can be effective in the intake amount of different amino acids. So, to confirm the findings of this study, it is suggested to conduct more studies in this field.

Food should contain enough amino acids to grow and maintain human health. For all practical purposes, the nutritional value of protein food is defined by its basic amino acid composition. In the sugar industry in particular, production and the importance of the final product, the presence of amino acids in each stage of sugar production, that briefly includes diffusion, purification, evaporation, crystallization, results in inappropriate color production and also one must remember that asparagine, is one of the amino acids that produces acrylamide. The aim of this research work is to investigate the profile of amino acids in the sugar industry, including thick juice and molasses. Amino acid profiles in these products were performed by analyzing 20 amino acids, most notably asparagine. In this study, samples of thick juice and molasses studied during seven day intervals to measure amino acid profiles. Different physico-chemical tests were performed to measure the quality of each sample. Finally, by employing HPLC, the amount of each amino acid was in all samples analyzed. The results showed that samples of thick juice contained high amounts of asparagine, followed by molasses.

Hypothermia increases bleeding during surgery, risk of ischemic heart disease and postoperative woundinfection. Intravenous amino acid increases cell synthesis and produces heat. Our goal was evaluating of the effect ofamino acid on intraoperative hypothermia under spinal anesthesia. This is a randomized, double-blinded clinical trial that 36 adults undergoing Hip Arthroplasty were randomlyassigned into two groups of 18 each. One group received Amino Acids solution (Aminoven 10%) 500ml (240ml/h)throughout spinal anesthesia, and control group received saline solution. We measured core body temperature, MAPand HR each 10 minutes, and also postoperative shivering, blood loss, operation time, postoperative BUN and Cr werecompared in two groups. Throughout surgery, the reduction in core temperature was more in the control group than the amino acidsgroup (statistically not clinically). The decrease in core temperature was significantly larger in the controls (0.96°C± 0.7°C) than in the amino acid patients (0.94°C ± 0.4°C), (P value= 0.02). Postoperative shivering was 73% in thecontrols regarding 11% in the amino acids patients. Overall, there were no significant statistical differences betweenother variables that we measured in two groups of patients. Amino acids infusion during spinal anesthesia exerted a thermogenic effect. Our findings showedhypothermia was less in the aminoacid group, and also postoperative shivering was more in the control group.Level of evidence: I

In different tissues of the body, proteins are important parts that are made up of building blocks called amino acids. Considering the wide applications of radioactive sources in industry and medicine, the need to study the attenuation characteristics of amino acids is determined.

To study the attenuation characteristics of five types of amino acids, MCNPX Monte Carlo code and XMuDat program were used. Linear and mass attenuation coefficients, half and tenth value layers, mean free path, effective atomic and electronic cross-sections, effective atomic numbers and effective electron densities were calculated. 57Co, 192Ir, 18F, and 116mIn gamma sources were considered for this study. To validate the theoretical results, the obtained values were compared with the available experimental data.

The difference between the theoretical and experimental results was less than 11%. The results showed that with increasing photon energy, the linear and mass attenuation coefficients and effective atomic and electronic cross-sections decreased, while the half and tenth value layers and mean free path quantities increased. Furthermore, the linear attenuation coefficients, the effective atomic and electronic cross-sections, as well as the effective atomic number values increased with increasing amino acid density, while the effective electron density behaves independently of the amino acid density.

The presented theoretical methods produced data similar to experimental results with fair accuracy, so by using these methods, attenuation properties of other amino acids can be obtained over a wide range of energies.

Fruit juices, especially lemon juice, are the most targeted food goods for adulteration and fraud in Iran. The aim of this study was to investigate the profile and concentration of free primary amino acids as a marker for adulteration in lemon juice.

Amino acids were determined with high‑performance liquid chromatography fluorescence. The limit of detection and limit of quantification were in the range of 0.008–0.01 ng/ml and 0.03 ng/ml, respectively.

The method is suitable for distinguishing authentic juices from drinking products that may contain little or no fruit juice. In our study, total amino acid concentration in natural lemon was 13.15 mmol/l and in other brands was in the range of 1.81–14.84 mmol/l. Further, the concentration of aspartic acid, glutamic acid, asparagine, and serine was more than other amino acids. The findings showed that only brands 1 and 2 were considered similar to natural lemon juice.

The present study demonstrated that the concentration of the first four amino acids can use as a marker to determine lemon juice adulteration.

Taurine (TAU) is the most abundant free amino acid in the human body. High concentrations of this amino acid are found in tissues such as the skeletal muscle, brain, and kidney. Recently, a focus has emerged on the effects of TAU on cellular mitochondria. It has been found that TAU could positively affect this organelle by enhancing mitochondrial membrane potential, increasing ATP levels, and mitigating mitochondria-mediated ROS formation. The current study aimed to evaluate the effect of a wide range of TAU concentrations (0.01 mM-1000 mM) on mitochondrial function. Mice liver mitochondria were isolated and exposed to different concentrations of TAU (30 min). Several indices, including mitochondrial depolarization, dehydrogenases activity, permeabilization, and ATP content, were monitored. It was found that TAU supplementation significantly enhanced parameters such as mitochondrial ATP levels and mitochondrial membrane potential in comparison with the control group. Moreover, TAU prevented Ca2+-induced mitochondrial permeabilization. This amino acid revealed no significant adverse effect on isolated mitochondria even at very high and supra-physiological concentrations (e.g., 100, 250, and 500 mM). These data suggest TAU as an ideal and safe agent to protect mitochondria against toxic insults or regulating cellular function in different mitochondria-linked disorders.

In this study the efficiency of two different morphologies of polysulfone adsorptive membranes was examined for the humic acid removal from contaminated water. Adsorptive membranes with finger-like and sponge-like pore structures were prepared using modified montmorillonite with amino acid. Structure of fabricated membranes was investigated by Field Emission-Scanning Electron Microscopy, pure water flux, porosity and contact angle measurement. The obtained results showed that the addition of modified montmorillonite (MMT) to the membrane with finger-like structure altered the morphology and improved pure water flux, porosity and hydrophilicity. These changes were negligible in PSf with sponge-like structure. In addition, the adsorption property of these membranes for the removal of humic acid (HA) was extensively studied. Adsorption capacity of cellular membrane was higher than the finger-like structure and Freundlich isotherm model was fitted for both of them. Nevertheless, the membrane with finger-like pores provides rapid adsorption of HA respect to cellular structure. It was also found that increasing the pH until pH=8 enhanced HA removal for adsorptive membranes, but increasing the pH above this point was not favorable. The obtained results from the dynamic adsorption revealed that sponge-like and finger-like membranes could generate 100 mL and 50 mL permeate of high quality (<1 ppm HA in water), respectively.

In the recent decades, starch has been modified using different methods for the various forms of applications. Some new starch derivatives were prepared through a simple and convenient method in the grafting of amino acids: L-alanine, L-leucine and L-phenyl alanine to starch.
First, the amine groups of amino acids were protected using phthalic anhydride then the acidic side of amino acids were activated with chlorination using thionyl chloride, and the resultant acid chlorides were reacted with starch in aqueous media at room temperature.
Performing the various spectroscopy experiments on the obtained compounds showed that the new derivative of starch has been formed. The structure of all synthesized materials was determined and confirmed using common spectroscopy methods and their thermal behavior was examined using DSC experiment.
New amino acid derivatives of starch and their nanocarriers successfully prepared through a simple and convenient method. The size of nanocarriers evaluated using DLS and TEM experiments. The spherical shape of particles shows that nanocarriers have been formed and the size of these particles are approximately 92, 137 and 97 nm. Performing the wettability test determined that all the resulted materials are soluble in water. Nanocarriers of the obtained modified starches were prepared using dialysis method and naproxen was utilized as a model drug molecule. The drug release dynamics in buffered solution were studied and investigation of the drug release mechanism showed that in case of L-alanine- and L-phenylalanine-modified starches, drug release followed the Fickian diffusion with a slight deviation.

Brain damage and mental retardation in children can be caused by either excess or depletion of certain amino acids. Up to now there is no reliable reference interval for free plasma amino acid in Iranian children.
The aim of this study was to provide the reference intervals of free plasma amino acid in healthy Iranian children using high performance liquid chromatography (HPLC) as an accurate method.
133 children referred to Children’s Medical Center, Tehran, Iran for the annual checkup entered the study after filling out the informed consent form. Demographic data and blood samples after overnight fasting were collected. Plasma amino acid concentrations were determined by reverse phase HPLC (RP-HPLC) equipped with a fluorescence detector after precolumn derivatization of amino acids with o-phthalaldehyde (OPA).
Female children exhibited significantly higher plasma concentrations of taurine and lysine than male children. Other 20 amino acid values were not significantly different between two gender groups. Positive correlation was obsereved between age and taurine, leucine and lysine.
Our data provided reference intervals of free plasma amino acids in healthy Iranian children. We believe our data can be used as a guideline for pediatricians to identify the significantly deviated amino acid values in children with medical issues such as genetic disorders and some acquired illnesses. Our data is also applicable for further investigations in the field of family medicine.